Ethnic differences seen in extremely obese children

Marked ethnic differences in the rates of extreme childhood obesity in New Zealand have emerged in a nationwide survey headed by University of Otago researchers.

The Ministry of Health-funded National Children's Nutrition Survey took body mass index (BMI) measurements of 3000 New Zealand children aged five to 14 years, with 1000 from each of three ethnic groups: Pacific Island, Māori and New Zealand European/Other.

While it showed a 2.7 per cent incidence of extreme childhood obesity - compared to 4 per cent in the United States - Pacific Island children stood out with a 10.9 per cent incidence of extreme obesity, with Māori children at 5.1 per cent and New Zealand European children at 0.8 per cent.

It is one of the few studies of its type done anywhere in the world and indicates that, of the 576,900 New Zealand children in the five-to-14-year age group at the time of survey, approximately 15,000 would be extremely obese.

Of those, about 6000 would be of Pacific Island ethnicity, with another 6000 Māori and 3000 categorised as New Zealand European/Other.

University of Otago Department of Medical and Surgical Sciences research Dr Ailsa Goulding says the ethnic differences in the prevalence of overweight and extreme obesity were substantial across all age and gender brackets.

"In Pacific Islanders, about one-third of the overweight children displayed extreme obesity, which is a higher proportion than occurred among NZEO or Māori.

"Extreme obesity was also more common among children having low socioeconomic status."

Dr Goulding says the findings that extreme obesity affects 1 in 10 Pacific Island children and 1 in 20 Māori children, compared to 1 in 100 NZEO children emphasises the need to identify affected individuals and provide them with help.

"These children are already so obese that it is bad for their health," she says. "They are in the top one per cent of the weight range for their age group and adults in that weight range usually have at least one health problem.

"We need to convey this to their parents because many of them don't realise the risks for children and don't associate it with bad health."

Dr Goulding says the study provides a strong case for urgent research into the underlying reasons for these ethnic disparities and ways to implement successful strategies to curb this severe obesity in children.

"Ethnic differences in severe obesity may originate from genetic factors, different patterns of eating and physical activity or low socioeconomic status."

Dr Goulding says that - given that diabetes and metabolic syndrome are prevalent in obese Māori and Pacific island adults, with type 2 diabetes occurring in these groups in adolescence - children with extreme obesity are at high risk for these and other related conditions.